Cryptographic apparatus



V. ViTA cRYPToc-RAPHIG APPARATUS Filed Aug. 4, 1927 HyI/ENTOR. Vi cen'e Vc a fm ATTORNEYS Feb. 14, 1928.

Patented Feb. 14, 1928. l

VICENTE VITA, DE WASHINGTON, DISTRICT OF COLIMBIA.

GBYIPTOGRAPHIC APPARATUS.

Application filed August 4, 1927. Serial No. 210,640.

The invention forming the subject matter of this application relates to an instrument for constructing messages in code and :forv

deciphering these messages. o

The main object of the invention is to provide an instrument composed of a lfew very simple elements relatively movable'to form code word-combinations Acorresponding to numbers or plain language words, or vice versa, of such great variety as to render `it practically impossible for any one to decipher a message without knowing the key number,and for the sake of clarity, there is herein described a'code system/adapted for use with the said instrument to provide the greatest possible secrecy in the employment of diplomatic and commercial codes.

Other objects of the invention'will become apparentes the detailed description thereof proceeds.

In the accompanying drawings,

Figure 1 is a plan view of the instrument;

, Figure 2 is avertical section on the line 2--2 of Figure 1; and,

Figure 3 is a plan of one of the semicircular disks of the instrument.

The instrument comprises a base plate 1 having three circular disks or plates 2, 3, and 4 respectively mounted to rotate freely and independently about a common center pin 5. The base plate 1 is provided with indexlines and y extending radially from the center of pin 5 and adjacent the circumference of the disk 2.

The disk 2 is of larger diameterthan the disk 3, which, in turn, is larger in diameter than disk 4. Superposed on the disk 4 and pivoted about the pin 5 is a semi-circular plate 6 ot substantially the same diameter as disk 4. Between the disks 3 and 4 a semi' circular plate 7 ot substantially the same diameter as diskA 3 is also pivoted at its center tothe pin i5; and a similar semi-circular plate 8, of practically the same diameter as disk 2, is pivotally mounted on pin 5 to rotate between the disks 2 and 3. j

The plate 6 is adapted to be clamped in any desired angular position on disk 4 by any suitable means such as the clip 9; and clips 10 and 11 may be used to clamp the plates 7 and 8 in any desired angular positions on the disks 3 and 2 respectively.

lt must be understood that the instrument itself may be embodied in many different mechanical v'forms without departin "from the principle' of the invention, Iand t e paru .on each line.

ticular embodiment described herein is taken in its simplest form to illustrate the princi ples of the system. Various other modifica tions of the instrumental part of the invention will readily suggest themselves to persons skilled in this art, and the claims appended to this specification are intended to cover such modifications in their broadest aspects.

The code system proper, for purposes of transmission, is such that live code letters or figures represent a complete Word. Accordingly, the letters and iigures on the several disks and plates of the instrument are arranged so as to be read in groups of live letters or five figures to be read in lines coincldent'with a line joining the .index lines and y.

For convenience of description, and illustration the numbers on the several plates 6, 7, and 8 are read with reference to the line a', which may therefore, be considered as the figures or number indicatorywhile the letters on the underlying disks 2, 3, and 4, are read with reference to the index line je] which may therefore be considered as the letters or word indicator.

In the particular embodiment of the invention shown in the drawing there are `one hundred equi-angularly spaced radial, lines 12, drawn on each of the semi-circular plates 6, 7, and 8; and numbers 13 are inscribed The numbers and lines on the plates 6, 7, and 8 are `arranged between the outer arcuate edges of the plates and semicircular lines 14, 15 and 16 on the respective plates 6, 7, and 8; and, in ellect, constitute substantially Semi-annular numerical scales, each of which has one hundred divisions or graduations. ,For convenience of description,`these numeral scales are designated by the reference characters 17, 18 and 19 respectively, and each numbered from 00 `to 99.

On the wcircular disks 2, 3 and 4, immediately below the plates 6,7, and 8, the letdial lines 28, and therefore, have thesame angular spacing as have-the lines 12 on the semi-circular plates 6, 7, and 8.

lin the various forms of this invention 1t is intended that the plates 6, and 8, or their equivalents sha-ll be divided. by one hundred equiangularly spaced radial lines, .and that the lettered elements will be divided in multiples of one hundred. For example, the circular disks may be divided into tour hundred equiangularly spaced radial divisions; and, since each division on the numbered plates must 4be equal to adivision on the lettered disks, it follows that the numbered plates must be substantially quadrants of a circle. Division of the circular disks into sin hundred spaces, would require number plates shaped as sectors, each comprising one-sixth of a circle. ln other words, the size ci the numbered plates is inversely proportionalI to the number in hundreds ot the divisions on the lettered disks, 4

Where the disks are divided into one hundred lparts only, the numbered plates will obviously `be complete circles, and the numbered scales must be oiset laterally relative to the letr scales in 'order that the latter may be read,

ln the operation oi this system, the' op erators must agree to use (l) A. particular code, dictionary commercial code, or any other book containing the words necessary for counication;

(2g A secret number oi ve gures ranging rom 00,000 to 99999;

(3) 'they must agree upon the positwn in a telegram or letter, sent from the message sender; to the receiver, of a ciphered or code word corresponding to the secret,number,

en the message is. received, the receive ing' operator rotates the number plates unm til the ve igures forming the secretn= ber, arealined with the number index a; and then, keeping these plates so positioned, rotates the lettered disks until the ve lettered code word corresponding tothe secret number is -alined with the 'word index y.

ln this position, the numbered plates are fastened Vto the res eetive' lettered disks so.

that each disk and t e plate fastened thereto rotate independently of the other disks and plates, j p

e When the parts of the instrument are set up as just described, the receivi o erator takes the rst cypher word in the te egram or message, and rotates the disks, with the number plates fastened thereto, in one difrection or another until the tive letters et `location of a word in the book agreed upon,

any convenient system may be Jlollowed; for example, the rst three nbers may reto the angular spacin jlmes on the irst name members, and means netas-ee der to the page of the book and the last two numbers may refer to the location of the word on the page, counting from the top or bottom or other location as agreed upon.

The device may also be used independently oi any book or key numbers, by providing the numbered disks with a series of letters 24C, which may be used independently of the numbers'to form words in a manner which will be obvious to persons skilled in the art,

The essential part of this; system involves the adjustment of the numbered plates over the lettered disks immediately below each of them, and the xing of these plates to these disks for decoding purposesu 'l claim 1. A code instrument comprising a support; three annular members rotatable about a common center on said support, eac-h having a series of equia-n ularly spaced lettered radial lines inscri ed thereon, and three semi-annular members rotatable on said support about the same center, each having a series of equiangularly spaced numbered lines inscribed thereon, the ane gular spacin between the numbered lines on the secon named members being equal to the angular spacing between -the lettered lines on the lirst named members,

.2. A code instrument comprising a support; three annular members rotatable about a common center on said sup rt, each having a series of equiangular y spaced lettered radial lines inscribed thereon, and three `semi-annular members rotatable on said support about the same center, each having a series oi equiangularly spaced numbered lines inscribed thereon, the anguiar spacing between the numbered lines on the second named members being equal between the lettered for securing each oi said numbered members to one of said lettered members,l Y 3. A code instrument including a base plate, a circular disk rotatably mounted thereon, and having an annular series of equiangularly spaced lettered radial lines thereon; a semi-circularl plate of the same diameter as said disk and having a semiannular series of equi-angularly spaced numbered radial lines inscribed thereon;

saidl plate `being superposed on ASaid disk; Y

androtatable independently thereof about the same center; and meansl for securing said plate in any desired position on said disk.

4, A, code instrument comprising a base plate; a circular disk rotatable about oui said baseplate; a semi-circular plate of the same diameter as said disk and superposed thereon to rotate independently about the same center; a second circular disk of smaller diameter than the first named disk and superposed on said plate and first named disk to rotateindepende'ntly thereof about the same center; and a second semi- ,circularvplate of' the same diameter 'as said second disk superposed on the said second disk to .rotate independently thereof about the same center, and adjustable means for securing each of said plates to the disk immediately' below it; said disks and plates being provided with cooperative coding indicia.

5. The combination with fthe instrument set forth in claim 4 of a third circular disk superposed rotatably about the same center on the seco'nd named plate and disk; and a third semi-circular plate, of the same diameter as the third disk and smaller than each of the other disks, vs upe'rposed rotatably about .the same center, on the, said third disk; veach disk being provided with an an nular series of equiangularly spaced lettered radial lines adapted to aline with the radial lines on the other disks; and each semicircular plate being provided with a semiannular series of equiangularly spaced numbered radial lines, adapted v to aline with the radial lines on the other disks and 'plat-es; and said'base plate being provided with a radial inde'X-line'for said numbered lines, and with a secondindex line for the lettered lines on s'aid disks. 6.' `A'code instrument including a support ,ha-,ving index marks thereon; relatively movable members each having a serles of lettered indicia inscribed thereon; relatively movable elements arranged movably in alternation-With said members and'having numbered indicia inscribed thereon; the in.

set forth in claim 6 of .means for securing.

each of saidelements to one of the members adjacent thereto. V

In testimony whereof I aix my signature.A

VICENTE VITA. 

